autocratically? самодержавно for the phrase "I'm not making these rules up as I go along" => I'm not making these rules autocratically (?)
I presume if you didn't mean politics and tzars you probably wanted to say "сам(а)", or "по своей инициативе",or "самостоятельно" or "единолично", or "как мне заблагорассудится", didn't you?